1. Field of the Invention
The present invention relates to a palm-sized character input device based on a keyboard having ten numeral keys (hereinafter referred to as the xe2x80x9cten-key boardxe2x80x9d) for use with a wireless information terminal such as a mobile telephone or a wired information terminal, which permits a user to input characters with one hand while holding the input device with the other hand.
2. Prior Art
Information terminals such as mobile telephones, which involve frequent inputting of numerals, are often used with an input device of a ten-key board type as illustrated in FIG. 2. The illustrated terminal has keys for inputting numerals from xe2x80x9c0xe2x80x9d to xe2x80x9c9xe2x80x9d with laterally three keys and vertically four lines and utilizes for inputting characters as well. The actual input method comprises allocating a plurality of alphabet letters to each of the numeral keys based on the alphabetic order, selecting a desired alphabet letter by depressing an associated key a plurality of number of times, and inputting the selected alphabet letter.
For example, when the numeral key xe2x80x9c9xe2x80x9d is depressed four times, an expressed character changes from xe2x80x9cWxe2x80x9d, xe2x80x9cXxe2x80x9d, xe2x80x9cYxe2x80x9d to xe2x80x9cZxe2x80x9d by each depression to select the character xe2x80x9cZxe2x80x9d.
A keyboard arranged in the qwerty order illustrated in FIG. 1 was devised in the 19th century, and is most widely spread over the world. Most of personal computers used in Japan also employ the same key arrangement. However, since a small-sized character input device for use with a mobile telephone or the like encounters difficulties in accommodating keys for 26 alphabet letters, the qwerty arrangement cannot be employed. Although personal computer users, in particular, usually input characters with both hands on a qwerty keyboard, they are forced to input alphabet letters on a small-sized character input device, which is directed by the present invention, based on the alphabetically ordered keys which however are not familiar to them. The users fully know the one-dimensional order of the alphabet letters from A to Z. However, the users must learn from the beginning the positions of alphabet letters allocated two-dimensionally on a keyboard.
It is therefore an object of the present invention to provide a ten-key board, having a less number of keys than a qwerty keyboard, which reproduces the input feeling on the qwerty keyboard that has been two-dimensionally memorized by personal computer users and so on.
According to the first embodiment of the present invention, there is provided a ten-key board type character input device for use with a wireless or a wired information terminal, which comprises:
ten keys provided on said character input device, a switching means for switching allocation of characters to the respective ten keys, a sensor for detecting a state of the switching allocation and an electronic circuit for switching the allocation of characters based on a signal from the sensor;
said switching means includes three switching functions to reproduce the qwerty arrangement, said three switching functions comprising:
a first switching function for allocating 9 characters positioned lateral 3 keys and vertical 3 lines on the left side of 26 characters in the qwerty arrangement to lateral 3 keys and vertical 3 lines at the same positions on said ten-key board among lateral 3 keys and vertical 4 lines of the ten-key board;
a second switching function for allocating 9 characters positioned in a central portion of the 26 characters in the qwerty arrangement to the keys on said ten-key board; and
a third switching function for allocating the remaining 8 characters on the right side of the qwerty arrangement to the keys on said ten-key board.
According to the second embodiment of the present invention, there is provided a ten-key board type character input system having the above system, wherein:
said sensor for detecting the state of the switching allocation is an inclination sensor or an angular velocity sensor provided at the character input device; and
said inclination sensor or said angular velocity sensor for sensing whether said character input device is inclined to the left or to the right or is at a normal position;
said electronic circuit controls said switching means to reproduce the predetermined number of characters on the left side of the qwerty arrangement on said ten-key board when said sensor senses that said character input device is inclined to the left, to reproduce the predetermined number of characters in the central portion of the qwerty arrangement when said sensor senses that said character input device is at the normal position, and to reproduce the remaining characters on the right side of the qwerty arrangement when said sensor senses that said character input device is inclined to the right.